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DH8D / B737, Winnipeg Canada, 2014
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Revision as of 22:20, 23 November 2019 by Validator1
|On 4 August 2014, the crew of a DHC8-400 departing Winnipeg continued beyond the holding point to which they had been cleared to taxi as a B737-700 was about to land. ATC observed the daylight incursion visually and instructed the approaching aircraft to go around as the DHC8 stopped within the runway protected area but clear of the actual runway. The Investigation found that the surface marking of the holding point which had been crossed was "significantly degraded" and noted the daily airport inspections had failed to identify this.|
|Actual or Potential
|Ground Operations, Human Factors, Runway Incursion|
|Flight Conditions||On Ground - Normal Visibility|
|Aircraft||BOMBARDIER Dash 8 Q400|
|Type of Flight||Public Transport (Passenger)|
|Intended Destination||Thunder Bay International Airport|
|Take off Commenced||No|
|Type of Flight||Public Transport (Passenger)|
|Intended Destination||Winnipeg International|
|Take off Commenced||Yes|
|Flight Phase||Missed Approach|
|Location - Airport|
Inadequate Airport Procedures,
Copilot less than 500 hours on Type
|Tag(s)||Aircraft / Aircraft conflict,|
Surface Lighting control
|Tag(s)||Incursion pre Take off,|
|Damage or injury||No|
|Causal Factor Group(s)|
On 4 August 2014, a DHC8-400 (C-FOEN) being operated by Westjet Encore on a scheduled domestic passenger flight from Winnipeg to Thunder Bay as WEN3112 continued taxiing beyond the holding point for an expected intersection departure from runway 36 in normal day visibility and only stopped when instructed to do so by ATC. A Boeing 737-700 being operated by Westjet as WJA318, which had been on short final to land on the same runway and had already received landing clearance, was instructed to go around.
An Investigation was carried out by the Canadian TSB. The event was not notified to the Board until the following day and the DHC8-400 CVR data relevant to the incident were found to have been overwritten. Data from the FDRs removed from both aircraft were downloaded but only the 737 data was of sufficient positional accuracy to be of any use. The TWR ASDE recording was available. The runway holding point did not have a lit stop bar.
It was established that the DHC8 had initially requested and received from GND a taxi clearance for a full length departure from runway 36. Shortly after this taxi had begun, with the aircraft commander as PF, the First Officer had requested a new clearance to proceed via runway 31 for a take off from the intersection of runway 31 with runway 36. This was approved with the instruction to hold short of runway 36. The diagram below shows both routes.
The aircraft was transferred to TWR and the instruction to hold short of runway 36 was repeated with the information that there was an aircraft about to land on it. The First Officer acknowledged this as the aircraft was passing the clearance limit but soon afterwards, the commander, aware of the approaching runway and the notified clearance limit and having not seen the holding point markings or runway guard lights, stopped the aircraft. Having visually observed the incursion and confirmed it on the ASDE, the TWR controller instructed the 737 to go around, which it did. The nose of the DHC8 was found from the ASDE recording to be approximately 47 metres from the edge of runway 18/36.
It was found that the DHC8 Captain had accumulated 500 hours on the aircraft type having joined the Operator just under a year earlier as a First Officer and then been promoted to Captain just over three months prior to the investigated incursion. The First Officer had 71 hours experience on the aircraft type having recently joined the Operator and had being released from aircraft type training just over three weeks prior to the incursion.
It was found that the holding point marking which the aircraft had crossed had been co-incident with the boundary of the 60 metre runway protection zone applied at Winnipeg and co-incident with runway guard lights and signage. However, it was found from satellite imagery that the pavement surface marking had been missing from approximately 37.5 meters of the central section of the runway width - slightly over half of that width. This marking had last been repainted nearly a year earlier, with the usual 6 monthly painting interval being extended because of the continuous active runway status of runway 13/31 whilst runway 18/36 was out of service.
It was also found by inspection on site that the left hand runway guard light was so far out of correct alignment that it would have been invisible to pilots of taxing aircraft. It was noted that "this misalignment was not identified in the daily airport inspections". It was also noted that the orientation of signage and the correctly aligned right hand runway guard light were both optimised for traffic approaching along runway 31, rather than joining it from taxiway 'V'. It was also found that at the time of the incursion, the intensity setting for both runway guard lights had been at its lowest level 1, which was contrary to the requirement in the TWR Operations Manual that “Runway Guard Lights shall be operated at all times, with intensity 3 selected during daylight”. It was noted that intensity settings were adjusted from a panel in the TWR but that there were "no procedure for the controllers to verify the intensity settings".
It was noted that runway 18/36 had recently been returned to service after a period of closure lasting just over three months for land drainage repairs and resurfacing which had meant that runway 13/31 had been the runway in use. It was found that although a "Hazard Identification and Risk Assessment" for the construction project had identified the fact that single runway operations would "reduce the ability to conduct maintenance on the operational runway", the "documented ongoing risk control for this hazard relied on routine inspections and maintenance to identify and mitigate deficiencies". It was found that routine airport inspections were conducted by the airport duty manager and the airfield maintenance staff "at least every 24 hours" but there were "no checklists or documented procedures" for this activity. It was noted that the "construction plan" had specified that a "construction zone" extending 100 feet from the edge of runway 18/36 should be inspected prior to the re-opening of the runway but that this zone did not include the intersection holding point. The area where the incursion occurred is detailed with annotations on the diagram below.
The formally documented Findings of the Investigation were as follows:
- Causes and Contributing factors
- The hold-short line painted on Runway 31 southeast of Runway 36 was significantly degraded, with 123 feet of the line missing. As a result, the crew of WEN3112 did not see it and stopped in the runway protected area.
- The daily airport inspections at Winnipeg Richardson International Airport (CYWG) did not identify the degraded condition of the hold-short line, allowing continued use of the hold-short position.
- The orientation of the runway holding position signs was optimized for traffic on Runway 31, which likely contributed to the pilots not identifying the hold-short position.
- The fact that the left runway guard light (RGL) was aimed 15 degrees away from Runway 31, the orientation of the right RGL relative to the aircraft’s position, and the reduced RGL intensity setting likely contributed to the pilots not identifying the hold-short position.
- If there are no checklists or documented procedures for airport inspections, then there is an increased risk that non-compliance with regulatory requirements or safety deficiencies will not be identified.
Safety Action taken as a result of the Investigation by Winnipeg Airport Authority was noted as having been the repainting of the degraded hold-short line on Runway 31 and the realignment of the runway guard light located on the left side of Runway 31 southeast of Runway 36, as well as the incorporation of "new procedures for return-to-service inspections" and the introduction of "computer-based inspection tracking software that contains checklists and intervals for specific airfield elements inspections".
The Final Report of the Investigation was authorised for release on 16 December 2015 and released on 21 December 2015. No Safety Recommendations were made.